You may leave any cards with that name in the player’s graveyard, hand, or library. You don’t have to exile them.

8/25/2015

Cards with devoid use frames that are variations of the transparent frame traditionally used for Eldrazi. The top part of the card features some color over a background based on the texture of the hedrons that once imprisoned the Eldrazi. This coloration is intended to aid deckbuilding and game play.

8/25/2015

A card with devoid is just colorless. It’s not colorless and the colors of mana in its mana cost.

8/25/2015

Other cards and abilities can give a card with devoid color. If that happens, it’s just the new color, not that color and colorless.

8/25/2015

Devoid works in all zones, not just on the battlefield.

8/25/2015

If a card loses devoid, it will still be colorless. This is because effects that change an object’s color (like the one created by devoid) are considered before the object loses devoid.